Apple Event: May 7th at 7 am PT

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

iPhone 4 using Cellular Data when on standby and connected to wifi.

This is a real strange one. I have two wifi networks, one at home and one at work. I have recently upgraded to the iphone 4 so I have lost my unlimited data tariff so I thought I would have a look at what data was being consumed on the phone. I have noticed that although I am connected to wifi on both networks, if I just leave the phone so the screen goes black and it goes into its lock mode, when I press the home button to use the phone, for a second or so it shows 3G as the connection and then after about a second the wireless logo appears. This is sort of giving the indication that when in sleep mode it is dropping the wifi connection until I start using the phone again and wifi kicks back in. Sure enough if I then check the cellular data usage it has increased. Sometimes just by 1 or 2 kilobytes on sent and received, sometimes 20 or 30 kilobytes or more on both sent and received. This is without receiving any e-mails or any apps in the background running. This is happening on both the home and work networks, but it seems to consume more data on the work network. The only difference between the two is that the work SSID is hidden but I have set that up manually so the iphone sees and connects to it without any problems. The problem seems to arise when the phone is not used and goes into locked/sleep mode.

iphone 4, iOS 4

Posted on Jul 4, 2010 9:23 AM

53 replies

Jul 4, 2010 10:53 AM in response to Allan Sampson

Allan. To clarify, if I disable cellular data then I will not be able to send or receive data outside of a wireless connection. However if i enable cellular data I will have the choice to use 3G or not?

The reason I am seeking clarification on this is that the phone will allow you to enable 3G when cellular data is disabled which seems illogical.

Jul 4, 2010 10:59 AM in response to Spencer Simmonds

To clarify, if I disable cellular data then I will not be able to send or receive data outside of a wireless connection. However if i enable cellular data I will have the choice to use 3G or not?

Correct. You can disable Cellular Data access when connected to an available wi-fi network, and re-enable it when not within range of an available wi-fi network, or enable it only when needing internet access via the cellular network.

The reason I am seeking clarification on this is that the phone will allow you to enable 3G when cellular data is disabled which seems illogical.

You can enable/disable 3G network access when Cellular Data access is disabled so when turning on Cellular Data access, your chosen option for data or internet access via the carrier's network is enabled.

Jul 4, 2010 11:02 AM in response to Allan Sampson

Thank you. Makes sense.

Jul 4, 2010 11:05 AM in response to Allan Sampson

Now the option to automatically disable cellular data when connected to a wifi network would be a worthwhile update to the functionality of ios4 in my view.

bcmilne

Level 1

0 points

Jul 16, 2010 9:26 AM in response to Spencer Simmonds

yes, I know this is an older post, but I'd better get my two cents in. I've been trying to resolve this issue over the past week, after noticing that while connected to the charger, between 12-1 am, on the home wi-fi network, I had a 5 MB data transfer one night and a 10 MB data transfer the next night. That much data usage on a 200 MB plan is killing me. There were no e-mails with attachments, etc.

I contacted AT&T, when they didn't know anything, they said to call Apple Care (which went to a supervisor), which I did, and he said that it could be a carrier update, or it could be a 3rd party app, which only uses 3G and bypasses Wi-Fi. But there was no way to tell. Anyone know of an App that logs data usage?

From what I've read here in this thread it seems like Apple Care doesn't know anything about this issue. It was the first time the initial Apple Care support person heard about it. His supervisor knew only a little more.

Apple definitely should address this standby issue. I don't want to have to disable cellular data every time I think the phone's going to go into standby mode while it's surrounded by free wi-fi!

Jul 16, 2010 9:36 AM in response to bcmilne

Don't know what was downloaded so large but With iOS4, you can disable data access entirely, which you can do at night since you shouldn't need to access email or email attachments while sleeping or anytime to prevent data from being uploaded or downloaded via the cellular network when needed or wanted.

b_boult

Level 1

15 points

Jul 16, 2010 10:00 AM in response to Allan Sampson

Just to be absolutely clear, you are not charged for receiving emails right?

Jul 16, 2010 10:03 AM in response to b_boult

Incorrect.

Any data downloaded or uploaded via the cellular network - any data - browsing with Safari, downloading/sending email, 3rd party app access that uses or requires internet access is charged against your data plan.

bcmilne

Level 1

0 points

Jul 16, 2010 10:12 AM in response to Allan Sampson

What about during the day when it goes into standby mode? Night versus day it's the same issue. This phone should not be switching to cellular data when it enters standby mode, when it's already connected to a trusted network.

What would you rather have, a battery run down faster because of wi-fi, or have your cellular data used up when you're not using the phone?

PS. I don't understand how the wi-fi uses more battery than 3G in standby. Please explain.

Jul 16, 2010 10:22 AM in response to bcmilne

What would you rather have, a battery run down faster because of wi-fi, or have your cellular data used up when you're not using the phone?

I don't have to worry about it since I have an unlimited data plan. If I didn't have an unlimited data plan, I would go with the 2GB limit data plan. Over the last 3 years, I have gone over 200MB of data in a month a number of times, but not once have I used anywhere close to 2GB or even 1GB.

If I couldn't afford another $10/mo, I can't change the first design with the iPhone turning off wi-fi automatically after it has been asleep for a period of time, but I can change the 2nd design included with iOS4. I can enable or disable data access as needed, just as I can enable or disable wi-fi access, 3G network access, and Bluetooth access.

Copied from this link.

http://www.apple.com/batteries/iphone.html

+Turn off Wi-Fi: *If you rarely use Wi-Fi, you can turn it off to save power.* Go to Settings > Wi-Fi and set Wi-Fi to Off. *Note that if you frequently use your iPhone to browse the web, battery life may be improved by using Wi-Fi instead of cellular data networks.*+

bcmilne

Level 1

0 points

Jul 16, 2010 10:42 AM in response to Allan Sampson

Thank you. So it would seem logical, if battery life may be extended by staying on wi-fi, that it not be dropped to the less efficient cellular when the phone enters standby mode.

Jul 16, 2010 10:51 AM in response to bcmilne

You're welcome.

No, you are reading that wrong.

+Note that if you frequently use your iPhone to browse the web, battery life may be improved by using Wi-Fi instead of cellular data networks.+

This applies when frequently or actively accessing the internet. At night when you are sleeping, you are not actively accessing the internet at that time and battery life may be improved using Wi-Fi instead of cellular data network when actively accessing the internet ONLY. More battery is used to maintain a Wi-Fi connection when not being actively used than is used when connected to the cellular network when not actively accessing the internet.

You are not going to change this. Either up your data plan, or turn off data access completely when not needed, or when your iPhone is in sleep or standby mode.

b_boult

Level 1

15 points

Jul 16, 2010 3:58 PM in response to Allan Sampson

I still fail to understand why I'm charged for receiving an email AND YET I am not charged for receiving text messages?

Message was edited by: b_boult

Jul 16, 2010 4:05 PM in response to b_boult

Although SMS/MMS is technically data, SMS/MMS are exchanged over the same network as calls and has been available long before smart phones were available with internet access via the cellular network. "Dumb" phones or phones not in the smart phone category that don't have internet access via the cellular network or any other way can exchange SMS/MMS.

You are right - SMS/MMS should be included with the data plan, but SMS/MMS is such a cash cow and 99% profit, this will only change by law.

Jul 16, 2010 4:14 PM in response to Spencer Simmonds

Well first off you shouldn't have lost Unlimited data unless you CHOOSE to opt out for one of the new plans. When I first got my iPhone 4 I was asked if I wanted to keep unlimited. You might want to check on that if you want to get it back. My two cents...

iPhone 4 using Cellular Data when on standby and connected to wifi.